Method of forming axle housings



Jan. 30, 1934. E. RIEMENSCHNEIDER METHOD OF FORMING AXLE HOUSINGS Filed Feb. 10, 1931 2 Sheets-Sheet 1 a 1934- E. RIEMENSCHNEIDER 7 METHOD OF FORMING AXLE HOUSINGS 2 Sheets-Sheet 2 M M Z 4 6 m 4 3 MK 6 W 4b I W 4 a F a y a m A A w 5 V 5 w Z A I] w W 4 w z m v a J 5 q q |lfll|| 0 iil ili :n l

' Fray Patented Jan. 30, 1934 PATENT OFFICE UNITED STATES 1,945,079 ma'rnoo 0F FORMING AXLE HOUSINGS Ernest Rlemenschneider, Cleveland, Ohio, as-

signor to The Midland Steel Products Company, Cleveland, Ohio, a corporation of Ohio Application February 10, 1931. SerialNo. 514,774

6 Claims.

of the tubing to form a large diameter annulus tov provide additional material where required, or subsequently to "collapse axially to form a flange, or to collapse partially to form an expansion section of tubing.

For these and other purposes, it is often desirable to form an annulus having diameters at different portions along its length different from the. diameters which can be obtained by the methods above described. Further, annular swell is often required which is much longer and at the same time of much greater diameter than the tube or cylindrical stock. Very important in other cases is the formation of an annulus having a wall thickness substantially equal to the wall thickness of the original stock.

My present method makes, possible the accomplishment of these and other objects and enables me to form such swells or annuli and control the length, diamete and wall thickness comparatively accurately.

Fig. 1 is a longitudinal section of a piece of tubing showing the bulging or expanding apparatus in position prior to expansion, certain 'parts of the expander being illustrated in section,

Fig. 2 is a similar view showing the expander in its expanded position with part thereof and the lower die shown in section,

Fig. 3 is a side elevation of the expander element,

Fig. 4 is an end elevation of the same,

Fig. 5 is a side elevation of one end of an expanded section of the tubing showing the same slotted for subsequent forming operations,

Fig. 6 is a side elevation of the same after the forming operation to expand the arms of the bifurcated tube and shape them to constitute one half of the gear housing portion of an axle hous- Fig. '7 is a side elevation of a section of tubing having a larger diameter than the stock illustrated in Fig. 5, and

Fig. 8 is a longitudinal section through a modifled 'form of the apparatus for bulging the tubing and drawing out one end thereof.

In order to illustrate my present method and apparatus, I shall describe its use in connection with the manufacture of axle housings from tubular stock, as more fully described in my copending application Serial No. 505,876, above identified, the application of the principles of my invention to other uses being apparent from such illustrative example.

In my-method of forming axle housings, a tube or cylindrical blank 1, which may be slightly larger in diameter than the main body of the housing is subjected to axial pressure to swell into an outwardly bowed annulus 2, a portion of the tuberindicated by the dot-dash line 3, usually intermediate the end 4 and the main body 5. The tube is then slotted with diametrically opposite slots 6 which extend longitudinally part way through the annulus 2, forming arms 7 and 8. The inner end of the slots are preferably shaped, as illustrated, so that the edges thereof are parallel to the outer limits of the annulus 2. In succeeding operations the bifurcated forks 7 and 8, resulting from the slotting, are spread apart and formed into the enlarged flanged gear housing portion of the axle housing, as illuss trated in Fig. 6. In order to provide sufficient additional material for this spreading operation adjacent to the inner end of the slot 6, the wall thickness of the annulus must be held substantially the same as but preferably rendered greater than that of the original stock.

I accomplish these and other results by subjecting the tubing, either in heated condition or cold, to axial pressure and concurrent radial pressure, the radial and axial pressures being cor-' into the annulus to cause increased wall thickness or to compensate for what would otherwise be thinning of the annulus walls due to increase in diameter. In this manner an annulus having a wall thickness substantially equal to that of the original stock orihaving a different predetermined 5 wall thickness, if'edesired, may be formed.

In order to practice this method, I provide an expanding die arrangement which will now be described. The expanding apparatus includes a supporting post or die 10, over which one end,

for example, the end portion 4 of the tube may be placed. The post 10 is provided at its base with a shoulder 11 against which the end of the tube rests during the expanding operation. A die member 12 relatively movable toward and away from the die 10 is adapted to slip into the other or upper portion 5 of the tube. The die 12 is likewise provided with an annular shoulder 13 against which the other end of the tube rests, so that as the dies 10 and 12 aremoved relatively toward each other in an axial direction the tube is subjected to longitudinal or axial pressure. Expanding elements 14 which are movable radially inwardly toward and outwardly from the axis of the die members 10 and 12 are provided and preferably carried on the die member 12. Any number of such elements may be used, but experience has proven that by the use of six of such elements an annulus of substantially circular cross section throughout its length can be formed. Each of the elements 14 is provided with longitudinally separated wedge or cam surfaces 15 and 16, the surfaces 15 engaging complementary cam surfaces 17 on the member 12 and the surfaces 16 engaging complementary cam surfaces 18 on the die member 12 spaced longitudinally thereof from the surface 17. Instead of forming the surfaces 18 on the die member 12, they may be formed on a removable post 19, coaxial with the die member 12 and expanded or screw threaded thereinto, as illustrated. Each of the elements 14 rests at its lower end on a shoulder 21 on the member 20. The shoulder 21 preferably slopes slightly downwardly and outwardly from the die members 10 and 12 to insure free outward movement of the expanding elements as axial pressure is applied to the dies. The post 19 may have a downward extension 22 adapted to engage a passage, indicated at 23, in the die member 10 so as to retain the die members 10 and 12 in axial alignment during the expanding operation. Each of the elements 14 may be provided with circumferential slots 24 and 25 which are deep enough to receive springs 26 and 27 for holding the elements in position when the combination is withdrawn from the tube and for urging the elements inwardly of the die members 10 and 12. The cam surfaces 15 and 16 and the complementary cam surfaces 17 and 18 are disposed at'a slope upwardly and outwardly from the axis of the dies 10 and 12.

Variations may be made in this angle of slope, for instance, from 25 to 50 is effective, a less angle being used for a small diameter annulus relatively or slow spreading action and a greater angle being used for larger diameter or more rapid spreading annulus. As the angle increases, greater axial pressure is required and consequently the tubing is fed into the annulus at greater rate. By'varying the angle, the axial movement and radial expansion may be correlated to provide the material thickness desired in the armulus. In one case of tubing of the size used for axle housings and with an annulus of the diameter for practicing such process, I have found that by using an angle of 35 the radial expansion of the tubing and the downward movement thereof are correlated so that the tubing is fed inio the annulus from the upper end at about the in their innermost position and the outermost diameter thereof is equal to or slightly less than the diameter of,the tube. The tube preferably is positioned with the end 4 on the shoulder 11 of the die 10, as described. The die 12, carrying the elements 14, is inserted in the tube from the upper end 5 and forced downwardly, bringing the cam surface 17 and 18 of the die 12 into engagement with the complementary cam surfaces 15 and 16 respectively of the elements 14. At substantially the same time the shoulder 13 engages the upper end 5 of the tube and causes axial movement thereof.

Upon engagement of the cam surfaces 15 and 16 die members and guide the portion 3 of the tubing to form the annulus 2. At the same time the tubing is fed downwardly toward the annulus at' the desired rate for the particular wall thickness required. This movement continues until the elements 14 have been moved to an extreme outward position, as illustrated in Fig. 2, the expanding and guiding pressure being applied to the inner walls of the tube first near (he central portion of the annulus and while the pressure is continued on the central portion, the zone of application is widened axially therefrom to effect outward expansion of the sloping ends.

The die 12 is then withdrawn. When, as described, the annulus 2 is to be formed wih the ends gradually tapering inwardly to the diameter of the adjacent portions of the tube, the elements 14 are formed with inwardly sloping surfaces near the ends, as indicated at 30 and 31.

As the die 12 is withdrawn, the tapering end walls of the annulus engage the surfaces30 of the elements 14 and move them inwardly. Each of the elements 14 is provided with an inwardly the elements 14 inwardly upon withdrawal of the die 12.

- Obviously, by shaping the tube contacting surface of elements 14 as desired, and choosing the proper length of elements and adjusting the angle of the cam surfaces to conform to these changes, confining the tube on the outside if necessary,

an annulus of almost any desired length wall thickness, shape and diametermay be formed.

After the dies are removed, the end 4 and part of the annulus 2 of the tube are slotted axially with diametrically opposite slots, as described, and are engaged by dies to spread the bifurcated arms 7 and-8, thus formed, apart and to form the flanged gear housing portion of the axle housmg.

"member while the members are held in axial alignment. a

As stated in my copending application, Serial No. 505,876, it is often desirable to form an axle housing' from tubular stock larger in diameter than the main body of the housing. For example, referring to Fig. 7, the main body So of the housing is of much smaller diameter than the tubular stock, the original size of which is indicated by the dotted line 341. The use of such size of stock enables me to prepare the tube" with less draw ing. The outer end 4a may have the same diameter as the stock, thus providing considerable material for the arms of the gear housing portion. The annulus may be expanded, as described, but to a less degree, and the main body 5a of the tube reduced to the size of the finished housing. In this manner, I may form the annulus 2a and the main body 5a of the same relative proportions as above or form a proportionately larger annulus with considerably less expansion of the stock material. Furthermore, as will be apparent from the following description, the forming operation may be accomplished with a press which is lighter than the press necessary for practice of the other method.

In Fig. 8 is illustrated an apparatus adapted to perform the steps of reducing and expanding the tubing by the latter method.

- The expanding elements, cooperating cam surfaces and other related parts of this modified apparatus may be the same as in Figs. 1 to 4 and require no further description. Such parts, however, have been designated in Fig. 8 by the same reference numerals as in Figs. 1 to 4, followed by the suflix a, to avoid confusion.

In this apparatus, it will be noted that the position of the die members 10a and 12a is reversed, relative to the tube ends, so that the member 12a, carrying the expanding elements 14a is inserted into the outer end portion 4a of the tube, instead of in the longer end portion or body 5a. This relative reversal of position is necessitated by the reducing operation-which would preclude withdrawal of the expanding means from the end So. The member 20a is slidably carried on the post 19a of the die 12a, its axial separation from the post being prevented by a lug 40 so as to preclude its sticking in the tube and being lifted off from the post.

The die member or ram 10a is carried on a suitable head 41 of the press and is provided with a shoulder 11a. The die member 10a is of reduced diameter so as to fit with slight clearance into the body 5a of the tube after the tube is reduced. Carried on the head 41 is a carrier 42 having an opening 43 adapted to receive the reduced tube with slight clearance. Mounted on-the end of the carrier 42 facing the die 12a and concentric with the opening 43 are a plurality of reducing dies for reducing the end 5a of the tube. These dies may be the usual ring dies, such as indicated at 45 and 46, each having the large diameter end of the opening toward the die 12a.

. In operation, the head 41 is raised, lifting the die member or'ram and the ring dies so that the tube may be positioned with the end 4a over the die member 12a and resting against the shoulder 13a. The expanding elements 14a are then in their upward and inward position. when the tube is so positioned, the head 41 moves rapidly downwardly, and the upper end of the tube is engaged by the ring dies 45'and 46. As the downward motion of the head continues, the tube is driven through the ring dies 45 and 46 which reduce the diameter and cause concurrent lengthening of the tube and thickening of the walls. This action continues and the shoulder 11a engages the upper end of the tube. At this instant, relative movement of the body 5a of the tube and the ring dies ceases and all move downward as a unit.

Concurrently, the ram or die 10a engages the member 20a. Upon continued downward movement, the member 20a forces the expanding elements downward on the cooperating cam surfaces,

causing them to separate radially and guide the gradually swelling portion of the tube as it is upset by engagement with the shoulders lla and 13a to form the annulus 2a. The downward stroke of the press is now completed and the head 41 rises to the starting position.

If desired, a suitable clamp 49 may be provided for locking the end 4a of the tube to insure separation from the upper die combination.

The distance between the ring die'and expanding elements in the extreme downward position of the head 41 may be fixed so that a short length ofunreduced tube 50 remains between the end of the annulus 2a and the reduced portions of the main body 5a of the tube. In practice, I have found the use of two ring dies satisfactory, the dies forming gradually tapering portions 51 and 52 on the finished tube.

As stated, the use of this particular arrangement of dies is effective in permitting utilization of a lighter press since the reducing operations of the ring dies are completed before the begin ning of the expanding operation. To more clearly emphasize this'fact, I expanded in an unheated condition, a 3% inch tube of gauge suitable for axle housing with a pressure of seventy-five tons. The first reducing operation required only 35 tons and the second reducing operation twenty tons. Consequently a press heavy enough for the expanding operation only need be used. Obviously, cold forming of tubular or cylindrical stock by my method is very effective.

In as much as the reducing operation causes a downward fiow of the metal and the expanding operation follows instantaneously, the metal is started for the expanding operation by the reducing operation, and consequently the expanding operation requires less initial force.

It should be noted further that the ring dies enclosing the tube apply thereto a large amount of the pressure of the press near to the expanding portion of the tube so that great pressure does not have to be applied to the more distant upper end of the body portion 5a of the tube.

As set forth above, I do not intend to limit my invention to the particular uses herein enumerated, nor to the particular structure illustrated and described, but intend to include the use of my invention in connection with numerous methods of forming articles from tubular stock or strip stock welded to form a cylindrical blank, especially in the production of articles from comparatively heavy-gauge stock. For these various uses, the apparatus and method may be varied without departing from the principles herein set forth.

I claim:

. 1. A method of forming straight tubular stock into tubular blanks having .a large diameter end portion, and a larger diameter swelled portion incurrent axial and inward radial pressures to reduce the diameter of the main body thereof to a diameter less than the end portion and to cause part of the metal to move toward the portion to into the swelled portion.

2. A method of forming from straight tubular stock a tubular blank having a large diameter swelled portion near the end, including subjecta ing the tubing to concurrent application of the axial and inward radial pressures to reduce the diameter of the main body thereof and to cause part of the metal to move toward the portion to be swelled, continuing the axial pressure and arresting the inward radial pressure and applying outward radial pressure at the portion to be swelled and continuing the application of the axial and outward radial pressures to swell such portion and to continue the movement of metal into the swelled portion.

3. The method of forming an axle housing section consisting of subjecting a tube to axial pressure and concurrent outward radial pressure to expand the same and concurrently to move the ends relatively toward each other to increase the wall thickness of the expanded portion above that of the original tube, slitting one end of the tube to extend into the expanded portion at diametrically opposite points, separating the arms of the bifurcated portion, and then further expanding said arms and forming them into arcuate shape whereby the wall thickness of said arms substantially approximates the original wall thickness of the tube.

4. The method of forming an axle housing section consisting of subjecting a. tube to axial pressure to expand the same and to move the ends relatively toward each other to cause the wall thickness of the expanded portion to approximate that of the original tube, slitting one end of the tube to extend into the expanded portion at diametrically opposite points and to divide said end into a pair of arms, and separating the arms of the bifurcated portions and forming them into arcuate shape whereby the wall thickness of said arms substantially approximates the original wall thickness of the tube.

5. The method of forming an axle housing section consisting of subjecting a tube to axial pressure while guiding aportion of the same radially outwardly to expand the latter while concurrently moving the ends of the tube relatively toward each other to cause the wall thickness of the expanded portion to approximate that of the original tube, slitting one end of the tube to extend into the expanded portion at diametrically opposite points, and separating the arms of the bifurcated portion and forming them into arcuate shape whereby the wall thickness of said arms substantially approximates the original wall thickness of the tube'.

6. The method of forming an article consisting of subjecting a tube to radial pressure to expand the same While moving the end relatively toward each other to cause the wall thickness of the expanded portion to approximate that of the original tube, slotting the tube at diametrically opposite points to divide said portion into a pair of arms, and separating the arms of the slotted portion and forming them into arcuate shape. 

